PLoS ONE (Jan 2021)

Plasma circulating cell-free mitochondrial DNA in depressive disorders.

  • Johan Fernström,
  • Lars Ohlsson,
  • Marie Asp,
  • Eva Lavant,
  • Amanda Holck,
  • Cécile Grudet,
  • Åsa Westrin,
  • Daniel Lindqvist

DOI
https://doi.org/10.1371/journal.pone.0259591
Journal volume & issue
Vol. 16, no. 11
p. e0259591

Abstract

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BackgroundPlasma circulating cell-free mitochondrial DNA (ccf-mtDNA) is an immunogenic molecule and a novel biomarker of psychiatric disorders. Some previous studies reported increased levels of ccf-mtDNA in unmedicated depression and recent suicide attempters, while other studies found unchanged or decreased ccf-mtDNA levels in depression. Inconsistent findings across studies may be explained by small sample sizes and between-study variations in somatic and psychiatric co-morbidity or medication status.MethodsWe measured plasma ccf-mtDNA in a cohort of 281 patients with depressive disorders and 49 healthy controls. Ninety-three percent of all patients were treated with one or several psychotropic medications. Thirty-six percent had a personality disorder, 13% bipolar disorder. All analyses involving ccf-mtDNA were a priori adjusted for age and sex.ResultsMean levels in ccf-mtDNA were significantly different between patients with a current depressive episode (n = 236), remitted depressive episode (n = 45) and healthy controls (n = 49) (f = 8.3, pDiscussionDecreased plasma ccf-mtDNA in difficult-to-treat depression may be partly explained by concurrent psychotropic medications and co-morbidity. Our findings suggest that ccf-mtDNA may be differentially regulated in different subtypes of depression, and this hypothesis should be pursued in future studies.